In this proposal, the design, assembly and testing of a dual resolution image-guided confocal Raman microspectrometer in a compact instrument is proposed. The proposed system will consist of a handheld probe capable of providing three modes of information. (1) Color video imaging - will provide gross tissue imaging ( about 5mm x 5mm) and thus will guide the selection of interesting areas that require a closer look, (2) Bright-field confocal microscopy - will provide depth resolved morphological mapping from the center of the selected region ( about 300 mu m x 300 mu m) at a cellular level with a single point resolution of 0.75 mu m and (3) Raman microspectroscopy - will provide depth resolved biochemical evaluation of the selected region (same as confocal) with a resolution around 5-10 mu m to be optimized in the R21 phase based on signal to noise. The handheld probe will be coupled to a spectrometer and detector configuration that can compile, process and display all information required for tissue characterization in a compact instrument for clinical use as well research investigation. The instrument proposed here will be optimized for the detection of early skin cancer in a real-time, non-invasive manner as a diagnostic as well as surgical guidance tool.The specific aims of the feasibility phase (R21) of the proposed project are as follows; (1) Design and build a bench-top HIRM probe and instrument,. (2) Characterize Roman signatures of skin tissues in vitro and assess the feasibility of measuring it in vivo (3) Evaluate the parameters necessary to build a miniature HIRM device (4) Design the miniature HIRM probe and system based on the specifications determined in Aim (3). These objectives when achieved will show feasibility of the proposed work, determine the specifications and thus yield a design of a commercially viable, clinical useful handheld image-guided confocal Raman microspectrometer optimized for skin cancer detection.Once designed, the probe and system will be constructed and tested in the R33 phase of the proposal. The specific aims of the development phase of tile proposal are as follows; (1) Build and test the handheld probe and instrument using tissue phantoms and in vitro skin samples, debug system and modify design, (2) Characterize in vivo skin Raman spectra using the bench-top probe on 30 skin cancer patients and 30 normal volunteers, (3) Evaluate the basis for the differences seen in live tissue sections using the confocal Raman microspectrometer. (4) Use the final handheld probe prototype for skin tissue studies in vivo in 30 patients, (5) Develop diagnostic algorithms that distinguish between the various types of malignant and non-malignant skin tissues.The development of the proposed work will have a significant impact on health care by providing the potential for complete disease management with a single compact, sensitive detection tool. With the success of this technique, Raman spectroscopy can be applied to other organ sites such as the prostate and ovary as well as other diseases thus impacting a broader field in medicine.